/*
 * @Author: your name
 * @Date: 2022-03-18 08:52:48
 * @LastEditTime: 2022-03-18 16:29:03
 * @LastEditors: Please set LastEditors
 * @Description: 打开koroFileHeader查看配置 进行设置: https://github.com/OBKoro1/koro1FileHeader/wiki/%E9%85%8D%E7%BD%AE
 * @FilePath: \dataonline-ts\src\utils\authcode.ts
 */

function randomColor() {
  const r = Math.floor(Math.random() * 256)
  const g = Math.floor(Math.random() * 256)
  const b = Math.floor(Math.random() * 256)
  return 'rgb(' + r + ',' + g + ',' + b + ')'
}

export default function DrawAuthCode(id: string, style?: {[key: string]: any}) {
  const canvasDom: HTMLCanvasElement | null = document.getElementById(id) as HTMLCanvasElement

  const canvas_width: number = canvasDom.offsetWidth
  const canvas_height: number = canvasDom.offsetHeight

  const show_num = []
  const context: CanvasRenderingContext2D = (canvasDom as HTMLCanvasElement).getContext(
    '2d'
  ) as CanvasRenderingContext2D //获取到canvas画图的环境，演员表演的舞台

  console.log(canvas_width, canvas_height)

  context.clearRect(0, 0, canvas_width, canvas_height)

  const sCode =
    'a,b,c,d,e,f,g,h,i,j,k,m,n,p,q,r,s,t,u,v,w,x,y,z,A,B,C,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,W,X,Y,Z,1,2,3,4,5,6,7,8,9,0'
  const aCode = sCode.split(',')
  const aLength = aCode.length //获取到数组的长度

  for (var i = 0; i < 4; i++) {
    //这里的for循环可以控制验证码位数（如果想显示6位数，4改成6即可）

    const j = Math.floor(Math.random() * aLength) //获取到随机的索引值
    // var deg = Math.random() * 30 * Math.PI / 180;//产生0~30之间的随机弧度
    const deg = Math.random() - 0.5 //产生一个随机弧度
    const txt = aCode[j] //得到随机的一个内容
    show_num.push(txt.toLowerCase())
    var x = 10 + i * 20 //文字在canvas上的x坐标
    var y = 20 + Math.random() * 8 //文字在canvas上的y坐标

    const fontSize = Math.floor(Math.random() * 16)

    context.font = `bold ${fontSize > 16 ? 16 : fontSize < 12 ? 12 : fontSize}px 微软雅黑`
    console.log(context.font)

    context.translate(x, y)
    context.rotate(deg)
    context.fillStyle = randomColor()
    context.fillText(txt, 0, 0)
    context.rotate(-deg)
    context.translate(-x, -y)
  }

  for (var i = 0; i <= 30; i++) {
    //验证码上显示小点
    context.strokeStyle = randomColor()
    context.beginPath()
    var x = Math.random() * canvas_width
    var y = Math.random() * canvas_height
    context.moveTo(x, y)
    context.lineTo(x + 1, y + 1)
    context.stroke()
  }

  return show_num
}
